Automatic zeolite softener



F. D. PRAGER AUTOMATIC ZEOLITE SOFTENER 7 Sheets-Sheet 2 Filed Oct. 12, 1942 INVENTOR.

O o m R E m P D F AUTOMATIC ZEOLITE SOFTENER 7 Sheets-Sheet 3 Filed Oct 12, 1942 Aug. 17, W43. F. D. PRAGER AUTOMATIC ZEOLITE SOFTENER '7 Sheets-$heet 4 Filed Oct. 12, 1.94:2

INVENTOR Filed Oct. 12, 1942 F. D. PRAGER AUTOMATIC ZEOLITE SOF'I'ENER '7 Sheets-Sheet 5 Aug. 17, 1948. F. D. PRAGER AUTOMATIC ZEOLITE SOFTENER Filed 001;. 12, 1942 7 Sheets-Shoot 6 ]N VEN TOR.

11 mm; 1?, 1948. F. D. PR AGE R I 2,447,477

AUTOMATIC ZEOLITE SOFTENER Filed Oct. 12, 1942 7 SheetsSheet 7 Patented Aug. 17, 1948 Frank D. rrager, Chicag Tank & Mfg. Co., Inc.,

ware

Application October 12, 1942, Serial 2 Claims. (Cl. 210-24) This invention relates to automatic zeolite softeners, filters and the like.

It is an object of this invention to provide a device of the type referred to, wherein all operating valves are individually controlled by a single pilot valve unit which comprises only two moveable valve members.

Another object is to provide a device of the type referred to, which is controlled by a simplifled arrangement of program switches, comprising only four electric switches for the complete operating and indicating program of a zeolite softener, and three electric switches in the case of a filter. I

Another object is to reduce the number and to improve the arrangement of the parts and mechanisms controlling a complete automatic program cycle, particularly eliminating all synchronous motors, clocks, hardness or pH testers, turbidity detectors, and the like, and using merely the standard water meter, which is always required, and which is very simply adapted to actuate the necessary switches and further control elements, in manner involving only the use of standard gears, electric magnets, and other standard parts, and eliminating all articles of special manufacture.

Another object is to provide a device of the type referred to, wherein the various positions of the apparatus are indicated by a simple, rotating dial and the same dial can be used to vary said positions, whereby the program cycle can be retarded or accelerated at will.

Other objects are to provide improved valve nests, improved hydraulic operators for the same, improved electric controls for the hydraulic operators, and suitable interlocking means for batteries of two or more units.

Still other objects may become apparent from the following disclosure.

In the drawing:

Figure 1A is a partial front elevation of an automatic softener plant incorporating this invention.

Figure 1B is a similar VieW compIeting this embodiment.

Figure 2 shows in detail the meter control device forming part of the plant of Figure 1B in front elevation with the front plate and other parts removed.

Figure 3 shows elevation.

Figure 4 shows in detail the pilot unit forming part of the plant of Figure 1B, with the cover and bonnet thereof removed, in front elevation.

the detail of Figure 2 in side Ill., asslgnor to Graver a corporation of Dela- 2 Figure 5 shows the detail of Figure 4 in sectional side elevation; Figure 6A is a partial diagram of electric connections in the apparatus of Figure 13 showing primarily that part of such connections that is contained in the meter control device Figure 1B. I Figure 6B is a similar diagram, completing that of Figure 6A into a complete diagram of said connections, and showing primarily that part of such connections that is contained in or closely associated with the relay box and pilot unit shown in Figure 1B.

Figure 7 is an enlarged detail of- Figure 13, showing a diaphragm al in longitudinal section.

' gravel IL The Figure BAis another enlarged detail of' Figure 13, showing a rate of flow controlling pilot valve and associated parts in front elevation; and

Figure 8B is a plan view, partly in section, of the valve shown in Figure 8A. Two softener tanks iii are shown, each of which contain a bed of zeolite ii supported on water is supplied to each softener and withdrawn from the same by a valve nest or system iii of pipes and fittings with six hydraulic, self-opening diaphragm valves ll, i5, i6, i1, i8 and I9 interposed thereon. These valves and the respective pipes may be identified as follows:

Influent valve It connects supply pipe 20 with top pipe 2 i Service valve I5 connects bottom pipe 22 with service pipe 23.

with bottom pipe 22.

Waste valve l1 connects top pipe 2| with waste pipe 24.

Brine valve IB' connects brine pipe 25 with top pipe 2 i.

Rinse valve i9 connects bottom pipe 22 with waste pipe 24.

Each diaphragm valve comprises an inlet port Bill, an outlet port 802, a partition 803 between said ports, a bonnet 8M, and a diaphragm 805 separating a hydraulic pressure the bonnet from the two ports, and adapted to allow or to break, communication between the ports.

A manual gate valve 26 may be interposed on the supply pipe 20 ahead of the valve nest i3, to be closed in case of repairs. Between the valve 26 and the valve nest IS, a water meter 21 is interposed on the supply pipe 20. v

The brine pipe 25 incorporates a hydraulic ejector 28 which draws concentrated brine from chamber 806 in,

a brine storage and measuring tank 29 through a tube 90 which is protected against reverse flow by a check valve 9| interposed thereon. The brine tank is normally kept full of concentrated brine by maintaining therein a supply of salt 32 on a bed of gravel 33, and adding makeup water through a small pipe 34 and float valve 39. The several flows are so arranged that a predetermined amount of brine is withdrawn from the brine tank 29 by the elector 28 when the brine valve i8 is open, while a smaller predetermined amount of makeup water enters the brine tank through the float valve 3! controlled by float 3 5A, riding on the surface of the brine in tank 29. Accordingly, a further float 39, which rides on the surface of the brine in the tank 29, is lowered at a predetermined rate as the brining operation goes on. When this float reaches a predetermined low position it operates a switch 31, which automatical- 1y terminates the brining operation, in manner to be described hereinafter. The float valve 9b is open at such time, so that thebrine tank is gradually refilled. When the brine tank is full, the float valve 35 closes, and the brine tank is prepared for another brining operation.

The softener waste and rinse diaphragm valves l1 and I9 discharge into a sump 39. ahead of a weir or orifice plate 99 in said sump, whereby a predetermined liquid level is maintained in the sump, in response to a predetermined rate of flow through the waste pipe 24. Two floats 49 and 4| ride on the liquid level in the waste sump 38 ahead of the plate 39. These floats serve to control the flow rate through the waste and rinse diphragm valves I l and i9, in manner to be described hereinafter.

The six diaphragm valves I4 to l 9 are primarily used as shut-oil valves, and their operation to such effect is hydraulically controlled by a program pilot unit 42 which in turn may be controlled electrically by a. meter control unit 43 on the flow meter 21. The group of six diaphra m valves is controlled through a cycle of four positions, which may be tabulated as follows:

These pilot valves are shown as conventional rotary valves; details will be apparent from Figures 8A and 88.

Each pilot valve has a rotatable valve member 99! siidably disposed in contact with a seat member 902, within a valve chamber 903 formed by said seat member and by a bonnet 904. Each valve member can be caused to perform a rotating, rocking movement by a valve stem 905 passing through the seat member, and to which the valve member is secured. Each stem in turn has a lever 908 secured to it, the free end of which is bifurcated, as at 907. Each float 40 and 4| has a float rod 908 secured to and upstanding from it and passing between the prongs of the bifurcated lever 901. These float rods and levers form the linkage 44; the rods engaging the levers by collars 909 adjustably secured to the rods, as by set screws M9. The pressure supply 46 communicates with each pilot valve chamber by an open part 9| i in the seat plate, so that the valve chamber 903 is constantly filled with water, under a certain pressure. A second port 9" in the seat plate is covered by the valve member 901 when this member, together with the lever 908 and float 40 or 4i is at a predetermined, low position; the valve member 90! gradually uncovers this second port 9l2 as the float rises. Each port 9" communicates with one of the pressure transfer tubes 41, 49.

Each branch connection tube 49 has interposed thereon a small restricting member 9|3. Member 9H3 is formed of metal, and is traversed by a passage 9. This passage is adjustably restricted by a member such as screw 9i5.

By proper adjustment of each set of collars999, a predetermined rise of the waste float as or 4! over a certain position causes the respective lever 996 and member 9M to rise, whereby port M2 is gradually uncovered and control pilot 45 admits pressure fluid to the respective diaphragm valve II or l9. This tends to close that diaphragm valve, against its self-opening tendency. The result is a reduction of flow, and drop of the float Valve 14 l5 l6 l7 l8 19 Service Position 0pm.-.- 0pm...- Backwash Position. Part 0pen Brining Position--. Rinse Position Except as indicated in the foregoing schedule, the diaphragm valves l4 to l9 are kept closed.

In the backwash and rinse positions, as noted in the foregoing schedule, the valves l1 and 19, respectively, are kept partly open, and the valve I4 is kept partly open together with the valve II. This feature of opening certain valves only partly is introduced for the purpose of providing a simplified and improved control of the respective rates of flow. Heretofore, separate valves of the butterfly or similar types have generally been used for this flow control. In the present system, each of the floats 49 and H in the waste sump 38, by means of linkage 44, controls a twoway control pilot valve 45. Each pilot valve has a pressure supply'46, and has joined to it a pressure transfer tube 47, 48, leading to the diaphragm' chamber of the respective hydraulic valve I! or l9. Each tube 41 and 48 has a restricted branch connection 49 leading to the waste sump 38, below the plate 39.

55 40 or H, until the proper flow rate is established.

At that point the control pilot 45 cuts oil" the pressure supply between the source 48 and the diaphragm valve I! or IS. The self-opening tendency of the diaphragm valve causes the same to expel water from the respective diaphragm chamber, through the branch 49. When, as a result, the flow rate in the respective pipe exceeds the predetermined value again, the float rides high again, and the valve is biased towards closed position again. Thus, the flow rates in the waste phragm chambers, and cutting the chambers of! from pressure. For this purpose, a pressure tube 50 communicates with transmission tubes to the diaphragm valves, through the ports of the program pilot, when the ports are uncovered by sliding valve members 5| and 52, associated therewith, There are eight pilot ports, 53, 54, 55, 58,-

51, 58, 59, and 50, which are correlated with the several diaphragm valves by transmission tubes 5| is connected to valve Port 58 under member 52 is connected to valve l9 by tube 58.

Port 59 under member 52 is connected to valves E6, 51, by tubes 53, 59.

Port 60 under member 52 is connected to valve 95 by duct 69 and tube 55.

The tubes may consist of copper tubing or the like, while the ducts may be formed in the body of the pilot valve unit itself.

It will be noted that the six diaphragm valves are connected to the'eight pilot ports by four simple tubes GI, 55, 55, and 68, and a fifth tube53 which has, instead of-a sixth independent tube, the branch 55. These tubes are used as hydraulic power supply conduits to the diaphragm valves. It will also be noted that there are three interconnecting ducts 52, 51, and 59 between three of the four pairs of pilot ports. There are only two movable valve members, 5| and 52,

The said ports are arranged in two parallel rows of four, in the sequence of the above tabulation, wherein the ports under either valve member 5| and 52 form a vertical row. The ports of each row are uniformly spaced from one another.

The duct 61 connects the upper-most or No. 1 port of the row under the slide member 5| with the uppermost or No. 1 port of the other row; that is, it interconnects the ports 53 and 51. Similarly, the duct 69 connects the lowermost or No. a port of the new under the slide member 5| with the lowermost or No. 4 port of the other row; that is, the ports 56 and 60. The third and last' duct 62 differs slightly; it connects diagonally the No. 2 port of the row under the slide member 5| with the No. 3 port of the other row; that is, the ports 54 and 59. The last two ports 55 and 58 are not interconnected by ducts. All ports are separate from each other except so far as they are interconnected by the said ducts.

- Each slide member 5| and 52, as shown in Figure 4, slides over the face 10 of the program pilot valve 42 wherein the several ports are formed. Each slide member 5| and 52 contacts the face 10 by two solid portions 1| and 12, which are spaced from one another by an open portion or passage 13. Thispass-age communicates with the hydraulic pressure chamber 14 below the bonnet 15 of the program pilot valve. The distances between centers of the solid and open portions of the slide members are equal to the distances between centers of the ports of a row.

. Each member 5| and 52 has a raised and a lowered position, in each of which the solid portions 1| and 12 of the slide member cover two of the four pilot ports in the respective row, which are spaced by one of the other two of the four pilot ports in the respective row,- said other two ports being uncovered. The arrangement ,of ports, solid portions and slide positions is such that in the normal, raised position, each slide member covers the odd number ports, or No. 1 and No. 3 ports, of the respective row, and uncoversthe even number ports, or No. 2 and No. 4, of the same row. This setting is reversed in the lowered position of each slide member.

It will be seen that only two movable pilot valve members 5| and 52, having two positions each, are required to control a complete program of four positions for the six hydraulic softener valves. This program may be summarized as follows 1. Members 5| and 52 up: Valve l9 closed by pressure through port 58 and tube 58; valves l5 and I1 closed by pressure through port 54, duct 52 and tubes 93, 54; valve it closed by pressure through ports 59 and 60 and tube 85; valves l4 and i5 (inlet and service) are opened by line pressure in port 8!, since they are cut off from their ports 55, 53 and 59'and accordingly have no pressure in the bonnet pressure chambers 80';

service position.

2. Member 5| down and -member 52 up:

Valves I4, i5, i8, and i9 are closed by pressure on ports connected thereto; the valves i5 and l! are cut on from bonnet pressure through the program pilot 42 and may only be partly closed through the respective control pilot 45,- the degree of opening, due to line pressure, being adjusted by linkage M; backwash position.

3. Members 5| .and 52 downz valves i4, I5, i5, and l! are closed by pressure on ports connected thereto; the valves in and I9 out ofi from bonnet pressure and opened by line pressure; brining position.

4. Member 5|,up and member 52 downz'valves i5. it, H, and it are closed by pressure on ports connected thereto; the valves-I4 and i9 are out oir from bonnet pressure through the program pilot 42; only valve i9 may be partly closed through the control pilot 45; rinse position.

In orderto actually enable each of the selfopening valves J4 to Hi to open, when pressure for the respective valve has been cut off from the diaphragm chambers thereof, I provide each diaphragm chamber, except as. hereinafter stated, with a bleeder outlet 1.5. These outlets may take the form of branch tubes connected to the respective pressure transmission tubes by T-connections 11, and restricted by orifice members 18, similar to the members 9|3, so that the I hydraulic valves may open gradually or at controlled speeds. The several branch tubes 15 discharge into the waste sump 38 below the plate one such branch directly connected thereto, or one for each of the branches 53 and 54,.

The pilot unit 42 has two electric solenoids I9 and 90, controlling the slide members 5| and 52 respectively through-levers 9| and 82. These levers are installed in the rear of the program pilot unit. Eachlever is raised by the respective solenoids when the latter is energized, and each lever is lowered by a counterweight 83 when the respective solenoid is deenergized, The levers 8| and 82 control the slide members 5| and 52 on the face plate 10 by means of rocking shafts 94, which are set-screwed to the respective levers and which extend through the pilot unit at right 7 angles to the face plate. When either solenoid 19 or 80 is energized and the respective rear lever 8| or 92 is raised, the respective slide member or 52 is lowered by a front lever85 tilted by the respective shaft 84 under the valve bonnet 15 The two solenoids 19 and 80, which through the pilot unit 42 control the six diaphragm valves I4 to I9, are in their turn controlled by a number of switches,- three-wire relays, and auxiliary mechanisms. Each three-wire relay comprises two poles s and T, a coil 0, and a resistor R; and a selfholding wire U may be provided. f

In addition to the aforementioned float switch 31, this system comprises three other switches 86, 81, and 88. These are controlled respectively, by cams 99, 90 and 9|. The three cams are adapted to be rotated by a series or system of gears 92, driven by the flow meter 21. The gears, cams and cam switches are contained in the meter control housing 43.

This series of-gears 92 may comprise a driving gear 92-A in meter 21; a gear 92-B driven by gear 92-A and substantially located in the meter control housing 43; a horizontal shaft 92-0 in said housing, whereon gear 92-13 is rigidly mounted; a gear 92--D rigidly mounted on shaft 92-adjacent the rear 'wall 49-A of said housing; additional gears 92-E, 92-F, 92-G, 92-I-I and 924, driven by gear 92-D and mounted adjacent said rear wall; said series 92-A to 92-J forming a speed reducing gear train as shown. The final gear 92-J of said gear train is rigidly mounted on horizontal starter control shaft means 93.

The meter 21 normally rotates the starter control shaft 99 forming part of system 92, through the normally closed clutch 94, interposed onthe starter control shaft, between gear 92--J and starter cam 89; the latter being rigidly mounted on the starter control shaft. This cam has a single, short, raised lobe, which at a, predetermined point actuates the starting switch 85. This switch is of the single pole, double throw type, and it now energizes the relays 95 and 96 through the conductor 91, since it closes the circuits A'85a95C-95R,-B and A-86-96C- 96R-B.

As the relays 95 and 96 are energized they complete self-holding circuits A95S--95U 950-95R-B and A95S95U-96C--98R,-B through one of their poles; they also prepare for the completion of two other relay energizing circuits and for the completion of a solenoid enerthree other poles. Thus, no actual changes in valve position result from the energizing of the relays 95 and 96 yet. However, an alarm device such as a hell or signal light (not shown) may be energized through the self-holding pole 958 of the relays 95, 96 in parallel with the relay coils 95C, 980 indicating to the plant operator or superintendent that the starting cam has begun to operate. Thus, the position of the system marked by the energizing of the relays 95 and 96 may be called'the alarm position. It is the last part of the softening position.

As the starter cam 89, driven as aforesaid, thereafter reaches that position which has previously been determined to mark the 100% exhaustion of the zeolite bed, it returns the double throw starting switch 88 to its original and normal position b in which it now closes the circuit A-85b-9 9-95T20098C98R-B and thereby energizes a third relay 98 through the condoctor 99 and one of the aforementioned closed sume rotation at the 100% or 0% position, al-

though in the meantime, some water flows through the meter 21, incident to the backwashing and rinsing operations. Furthermore, the relay 98 makes circuit A-98S-2II396T-204- 19-205-13, through the relay 9B for the solehold 19 of the pilot unit 42. This changes the gizing circuit to be completed later, by means of r softener I0 from softening to backwashing position.

As the starting switch 88 is reversed to b to energize the relay 98 as aforesaid, it also energizes a. fourth relay MI by a circuit A86b 99-I02- S-'-208.-I03T-201IOIC--IOIR-B, through the conductors 99 and I02, a closed pole of the relay 96, and a further, closed, interlocking pole I03T in the relay I03 associated with the second softener unit I0. The last mentioned pole I03T is normally closed. It will be understood that ordinarily the two softeners I0 should not be regenerated at the same time- Provision is made in the present system so that, on the one hand, at least one of the two softeners I 0 is always connected to the service pipe 23, but, on the other hand, the second softener can be regenerated immediately after the regeneration of the first. It will also be understood that each softener has an independent hydraulic valve system I9, pilot unit 42, meter control housing 43, and system of relays. The several relays, of course, can be contained in a common box I04. The relay I03 of the second unit corresponds to the relay 98 of the first unit as to construction, hookup, and in all other respects. If the second unit had reached the exhausted position of its starting shaft 99 before the first unit, then the relay I05 of the second unit would now be energized through the relay 98 of the first unit. It is assumed, however, that the first unit reaches the 100% exhausted position first, although the time-interval may amount only too. split second. After the relay 98 has been energized, upon the reaching of said 100% exhausted position of the first unit, the relay I05 of the second unit can no longer be energized, since the circuit through the normally closed pole of the rely 98 is interrupted. This interlock remains in eflect until the relay 98 is deenergized, as hereinafter referred to.

The series of gears 92, as mentioned, comprises a gear 92-E mounted adjacent the rear wall .49-A. This gear drives another gear 92--K,

similarly mounted, and the gears 92-A, 92-13, 92'D, 92--E, 92-K form a speed reducing gear train; the speed of gear 92-K preferably being greater than that of the aforementioned gear 92-J. Gear 92-J is rigidly mounted on horizontal shaft means I08; whereon are similarly mounted the cams 90 and 9|.

As the fourth relay I0! is energized, it makes self-holding circuit A Al0ISIOIU IOIC- IIlIR-B and also circuit A--IOIT-208I08-B for a solenoid I06, which now closes the normally open clutch I 01 interposed on the shaft I08 between gear 92-K and the cams 90 and 9i. This causes the said cams to rotate, as the backwash water flows through the meter. It will be re-. membered that the shaft 93 and starting cam 89 are at rest.

When a predetermined amount of backwash water has passed through the meter, the rotating function cam 90 throws a switch. This cam has a single, short, raised lobe, like the starting cam 89. At a predetermined point, the raised lobe on the function cam 90 closes the function switch 81. This switch is of the single pole, normally open type. It energizes now the fifth relay I09 through the conductor I I0,by circuit A--81- I I--I09C-I09R,-B.

As the fifth relay I09 is energized, it makes self-holding circuit A I 09S-I 09U-I 09C- I'09R-B, prepares for a relay deenergizing circuit, and also makes circuit A-I09S-209- 80-B for the solenoid 80 of the pilot unit 42. This changes the softener from backwashing to brining position.

When a predetermined amount of concentrated brine has been transferred from the brine tank 29 to the softener I0, the float 36 closes the float switch 31. This closes circuits A--95R-B and A-96R,B and thereby deenergizes the relays 95 and 96. This in turn, obviously, deenergizes the solenoid 19 of the pilot unit 42, changing the softener from brining to rinsing position. Thereafter, the float 36 rises again, opening the switch 31.

Incident to the rinse, water flows through the meter 21. When a predetermined amount of rinse water has passed through the meter, the rotating reset cam 9| throws a switch. This cam has an elongated raised lobe, engaging the reset switch 88. This switch is of the single pole, double throw type. It new changes to position and thus energizes the sixth and last relay III of the first softener unit I0, through the conductor 2I0.

As the relay III is energized, it makes selfholding circuit A-IIISlIIU--IIICIIIRB, prepares a relay deenergizing circuit, and also completes circuits A-I I IS--2 I l-I 09'I-2 I 2-'- 8812-13 and A-I I IS-2I I-I09T--2 I2-I09R B, deenergizing the relays 98 and I09, through the latter relay. The deenergization of relay I09 obviously causes the solenoid 80 of the piiotunit 42 to be deenergized, changing the softener I0 from rinsing back to softening position.

The deenergization of relay 98 obviously causes the solenoid I00 to be deenergized. Thus, the clutch 94 is allowed to close again, and the shaft 88 starts another, slow rotation, measuring another operating or service cycle of the zeolite bed II.- The deenergization of relay 98 also causes the normally closed pole 98T thereof to 10 tion shaft I08 to stop in zero position. From this position,'the function shaft can start again, causing a new backwashing operation-without delay, when the 100% exhausted position has again been reached in this softening unit. It will be understood that the zero-resetting period of the function shaft, which in this manner forms the first part of the softening period, need not be of any particular length; it merely uses so much of the circumference of the function shaft I08 as is not used for the various regenerating functions.

I claim:

1. In an automatic water treatment apparatus having four operative positions, a series of hydraulically operable valve members, a hydraulic pressure chamber associated with each of said valve members, a pilot unit at least one hydraulic transmission tube entering said pilotunit and each of said .pressure chambers, a pressure supply tube entering said pilot unit, a plurality of stationary ports in said pilot unit interposed between said pressure supply tube and said transmission tubes, ducts between some of said ports,

two moveable pilot valve members associated with said ports, each of said moveable members being adapted in-a first position to uncover some of said ports and in a second position to uncover others of said ports, and means adapted to set each of said moveable members into either of said positions, whereby a total of four pilot positions is obtained, corresponding to the said four operative positions of the water treatment apparatus.

2. An automatic water treatment apparatus of the type described in claim 1, wherein said means to set the moveable members in certain positions includes a solenoid associated with each of said moveable members, adapted when energized to hold the respective moveable member in one of the two positions thereof, means to energize each solenoid, and means associated'with each of said moveable members, adapted when the respective solenoid is deenergized to hold the respective moveable member in the other of the two positions thereof.

be closed, terminating the interlock and allowing the second unit to be backwashed, regenerated, and rinsed when or if it has reached the 100% exhausted position.

While softening service is thus resumed in the first unit and back-washing may start in the second, the reset cam 9| of the first unit is'still rotating. Finally, however, the raised lobe or this can disengages the reset switch 88 and returns it to 88. Thereupon this switch makes circuits A--88a--I I3-I l-IT--2'I3--I I IR-B' and A-llc-I Il-I I IT-2I3l0IR,-B through conductor II8 and relay III. deenergizingsaid relay and the relay IOI.

The deenerglzation of the relay IOI obviously causes the solenoid I06 to be deenergized, allowing the clutch I01 to open and causing the func- FRANK D. PRAGER.

REFERENCES crrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,354,311 Landrum Sept. 28, 1920 1,354,604 Duggan Oct. 5, 1920' 1,443,892 'Applebaum Jan. 30, 1923 1,608,091 Eisenhauer Nov. 23, 1926 1,608,661 Nordell Nov. 30, 1926, 1,644,469 Green Oct. 4, 1927 1,652,710 Dotterweich Dec. 13, 1927 1,787,686 Kerr Jan. 6, 1931 1,954,405 Dotterweich Apr. 10, 1934 2,051,155 Staegemann Aug. 18, 1936 2,056,420 Colby Oct. 8, 1936 2,061,797 Eisenhauer Nov. 24, 1936 2,065,962 Bowers Dec. 29, 1936 2,076,321 Pick Apr. 6, 1937 2,180,320 Hansen Nov. 14, 1939 2,217,822 Symons Oct. 15 1940 2,243,815 Griswold May 27, 1941 2,254,782 Riche Sept. 2, 1941 2,255,324 McGill Sept. 9, 1941 2,310,978 McGill et a1. Feb. 16, 1943 2,354,694 McGill et a1. Aug. 1, 19 

